Abstract:[Background] In the context of globalization and rapid advancements of biotechnology, the biosafety risks associated with microorganisms have aroused increasing concern, integrated into the national security system. Urumqi is a key node city in northwest China, and its wastewater treatment plants contain biosafety markers such as pathogenic microorganisms, which can serve as early warning signals for potential threats. [Objective] This study focuses on the microbial communities in the wastewater treatment plants of Urumqi. By analyzing the structural characteristics, diversity distribution, and potential biological risks of these communities, we aim to provide a scientific foundation for preventing the transmission of cross-border pathogens and maintaining regional bio-security. [Methods] Water samples were collected at a depth of 0.5 m from each of nine typical wastewater treatment plants in Urumqi in August 2 024. After processing, the samples underwent metagenomic sequencing. R (v4.4.2) was used for statistical analyses. Specific R packages were employed to calculate the α-diversity indices of bacteria and viruses, and non-parametric Kruskal-Wallis H tests were conducted to identify differences among the samples. Principal coordinate analysis (PCoA) based on Bray-Curtis distance and ANOSIM tests were performed to further understand the variations in microbial community structures across different sample groups. [Results] At the genus level, 300 microbial genera were detected, including 282 bacterial genera (94%), 2 fungal genera (0.67%), and 16 viral genera (5.33%), among which Aliarcobacter and Bacteroides were dominant. At the species level, 864 microbial species were identified, among which Aliarcobacter cryaerophilus and Cetobacterium somerae had high relative abundance. Alpha diversity analysis showed that the wastewater treatment plants S5 and S7 with integrated treatment processes had higher microbial diversity (Shannon indices of 3.398 and 3.421, respectively). Beta diversity analysis indicated overall similar microbial community structures across three sample groups, with no significant differences (ANOSIM R2=0.32, P > 0.05), though sample S4 deviated. Cluster heat-map analysis confirmed spatial distribution differences in microbial survival adaptability at various sampling points, with S9 and S1 having more positively correlated genera and different numbers of such genera at each point. The unique combination of arid hypersalinity, large low-temperature fluctuations, and a high-protein diet drove marked enrichment of halotolerant Arcobacter and psychrophiles. [Conclusion] The microbial communities in the nine wastewater treatment plants in Urumqi are dominated by bacteria, with specific genera and species. The plants with integrated treatment demonstrate higher microbial diversity and more pronounced spatial distribution differences in community structure. These findings provide valuable baseline data for regional biosurveillance and assessment of urban ecosystem health.
